Is there a relationship between occupational noise and hearing levels, sleep quality, and QoL of the factory workers?

Objectives: We assessed the hearing level, sleep quality, depression status, and life quality of the employees.

Methods: The research group contains 380 (56.7%) of 669 employees working in the factory. We used a questionnaire, noise measurement (2016), pure tone audiometry test results of (2015, 2016). SF-12 (short form), mini sleep questionnaire (MSQ), and Beck depression scale.

Results: The employees' mean working period is 13.5 ± 11.9 years. The mean ambient noise level of the factory is 75.5 ± 7.3 dB. We detected hearing loss at 18.6% and 23.2% in 2015 and 2016, respectively. The frequency of hearing loss is 4.7% at the employees working below 85 dB and 27.8% percent at the employees working above 85 dB. Mean working period of the employees with hearing loss (19.7 ± 11.7 years) is higher than mean working period of the employees without hearing loss(13.2 ± 11.8 years) (p < .0.05). The 27.8% of the employees working above 85 dB are used to earmuffs, 44.4% of them sometimes use earmuffs; 38.9% of them are used to earplug; and 44.4% of them sometimes use earplug. Back depression scales showed 31.1% minimal, moderate, or severe depression. The sleep quality of employees working above 85 dB is worse than the others (p < 0.05). SF-12 QoL scores were 39.41 ± 5.59 (physical health) and 36.10 ± 7.76 (mental health). There was not a statistically significant association between scale scores and ambient noise level and hearing level of the workers (p > 0.05).

Conclusion: We suggest the use of personal protective equipment. Working in the noise above 85 dB affected workers' sleep quality to be poorer.